Timepieces are already known, in particular astronomic watches which indicate the values of an astronomic magnitude with daily variation. These values are indicated by means of hands which are displaced by one step per day opposite a graduated scale a predetermined magnitude. However, here we are concerned with watches comprising highly complex movements with planetary gearing having multiple planet wheel sets. These mechanisms are thus of a very compact nature and consequently much too expensive to be manufactured by mass production methods. Furthermore, on such watches, the surface available for the display is relatively small to the extent that the reading of the astronomic values is not particularly easy and thus very often lacks precision.
On the other hand, astronomic watches are known presenting astronomic information through an opening provided in the dial. However, such information concerns astronomic magnitudes having an annual cycle with a constant value over the duration of a given month, for instance a sign of the zodiac. Here again, should one wish to display the value of an astronomic magnitude which varies daily, it is necessary to employ a disc effecting one rotation over 365 days, which likewise presents the difficulties mentioned hereinabove.
The principal purpose of this invention is thus to overcome the difficulties of the prior art by furnishing a timepiece enabling the display of the daily value of an astronomic magnitude having an annual cycle in a simple and precise manner and furthermore for only a small increase in the cost of the timepiece.